The aortic aneurysm was reportedly discovered after he was admitted to hospital for an unrelated issue.

A statement on his Facebook page on Monday read: "He apologises to all of his fans who were looking forward to the day, but assures everyone he will be back to full health and rocking out on stage with you all again very soon (he is in fact itching to do so!)"

"Thank you again to everyone who has taken the time to extend their well wishes for Jon's recovery. He sincerely appreciates your posts."

English migrated to Australia with his parents at the age of 12 and rose to fame in the early '70s after starring in Harry M. Miller's first production of Jesus Christ Superstar.

He released dozens of chart-topping singles in the '70s and '80s including Words Are Not Enough, Handbags and Gladrags, Turn the Page and Hollywood Seven.

His 1979 song Six Ribbons topped the charts in Europe and he received a Logie Award for best new talent for his acting in the series Against the Wind.

He also played the lead role of Bobby Rivers in 1990s Australian sitcom All Together Now opposite Rebecca Gibney and Today weather presenter Steven Jacobs.

Jacobs paid tribute to English on air on Thursday morning, calling him "a beautiful soul".

"I spent four years working with Jon on All Together Now, four of the best years of my life, along with Rebecca Gibney and the whole gang," he said.

"He was such a talented performer and such a gentleman, an incredible actor, an incredible rock star. He lived his life like a rock star, he was larger than life, but just a beautiful soul."

On Twitter, Gibney said his passing was "so incredibly sad".

"All Together Now was one of the joys of my career. My love to his family," she tweeted, adding on Instagram: "He was not only a wonderful actor, an extraordinary musician but he was a genuinely kind and lovely man."

English received accolades for his performances on both stage and small screen, starring in productions of Hair, Pirates of Penzance and Hairspray.

Gallaher praised him for his "incredible versatility" and knack for performing on stage.

"He made it look so spontaneous and that's the thing that I marvelled most. People who worked alongside us would marvel at his incredible craft."

"We worked and worked and did hundreds and thousands of those [Pirates of Penzance] performances and Jon never missed. Jon was always consistent and always funny."

A public memorial will be held in English's honour with details to be revealed shortly.

RIP Jon English. A great actor and true rock legend. An all round performer and gentleman. You will be missed mate.